Machine for stretching and compressing materials



March E, i936.,

J. H. V. FINNEY MACHINE FOR STRETCHING AND COMPRESSING MATERIALS Filed March l, 1935 M1111 Il H ll Il l] H l1 H INVENTOR.

ATTORNEY.

Patented Mar. 3, 1936 UNITED STATES i PATENT OFFICE MACHINE FOR STEETCHING AND CONIPRESSING MATERIALS poration of Colorado Application March 1, 1935, Serial No. 8,889

16 Claims.

This invention relates to improvements in machines for changing the length of strips o-f plastic or ductile materials and relates specifically to a machine for stretching or compressing strips of g. uncured rubber composition.

In the manufacture of automobile tires, the rubber which is to form the tread is first made into strips of the required width and length and these sometimes have a center o-f considerable my., thickness and thin edges. When uncured rubber composition is passed through a forming machine, it becomes quite warm while it is worked into the required shape,. and it has been found that if the strips are cut into the required length )5yy Without first compressing the material the sec tions will not shrink uniformly. It has been found that if the material is compressed sufciently before it is cut and cooled, the sections will have no further tendency to shrink and will therefore be of substantially uniform length when finished.

It is the object of this invention to produce a machine of simple and substantial construction which can be used for altering the length of a strip of plastic or other material by compressing or stretching the same over its entire width or over a portion of its width only.

This machine, briefly described, comprises two propelling devices so positioned that the strip 30, passes through both, one operates at a different speed than the other so that the material will be either compressed or stretched where it passes from one to the other.

Having thus brieiiy described the invention and pointed out its objects, the invention will now be described in detail, and for this purpose reference will be had to the accompanying drawing Where it has been illustrated in its preferred form and in which Figure 1 is a top plan view of a machine embodying the invention,

Figure 2 is a section taken on line 2 2 of Figure 1 and shows the machine in elevation, portions being broken away to better disclose the con- A struction,

Figure 3 is a section taken on line 3 3 of Figure 2, and

Figure 4 is a section taken on line 4 4, Figure 2.

50.l In the drawing reference numeral 5 designates the vertical members of frames of the shape of a gure 4, of which there are two; the other members have been designated by reference numerals 6 and 'I. 'Ihe frame can, of course, be constructed 551;- in a. variety of specifically different ways, and

will therefore not be described with any great particularity.

Secured to the frame members 1 are pairs of bearings 3 and 6 in which are journalled driveV shafts I0 and II. The two pairs of bearings 6 and 9 may be identical and the shafts II and I0 may also be identical except as to length. Shaft l! is provided at one end with a sprocket wheel I2, with which the sprocket-chain I2 cooperates to transmit power to the machine. The other m ends of shafts I6 and ll are interconnected by means of gears i4 and l5 of which gear I4 is carried by shaft It and in the actual machine has ninety teeth, while gear I5 is connected to shaft Ii, and has eighty teeth. It is therefore 15A evident that shaft lil rotates slower than shaft I I. Secured to each of the shafts are a number of sheaves i6, each of which has a hub I1 which serves as a bearing for an idler I8, (see Figures 3 and 4) shown as provided with ten sheaves and ten idlers, but a smaller or larger number can be employed. The sheaves and also the idlers are all alike and can be interchanged. The idlers I8 are of greater diameter than the sheaves, as 25,

clearly shown in Figures 3 and 4. The sheaves are grooved for the reception of V-belts I9, and the idlers are so spaced that the distance between their adjacent surfaces is slightly greater than the width of the belts. 30-

Pivoted to shaft I@ between the bearings 8 andy the collars 26 are arms 2|. One end of each arm extends to the right of the sheave and idler assembly on shaft IIJ, and are connected by a shaft 22 on which are journalled a number of 35` sheaves 23, which lie in the planes of the idlers on shaft II).

The other ends of arms 2| are provided with weights 24 that can be moved along the arms and may be providedA with set screws 25 for holding 40A them in adjusted position.

Belts IS which encircle the sheaves I6, carriedV by shaft Il, and corresponding sheaves 23 on shaft 22, are tensioned by the action of the lever arms 2 i, in a manner quite clear from an inspec- 425 In the drawing the machine has been 20 in staggered relation to the latter. Belts I9 encircle the sheaves I6 on shaft I0 and sheaves 23 on shaft 26, and are tensioned by the action of the weights 24a.

When the machine operates, shaft II rotates faster than rshaft I0, and belts I9, driven from the sheaves carried on shaft II, travel faster than those driven from the sheaves carried by shaft IIJ.

Let us now assume that a strip of raw rubber composition 2'I is fed into the space between the peripheries of the idlers I8 on shaft Iii and the belts I9 that are driven from shaft II and that the parts are rotated in the direction of the arrows in Figure 2. The strip 2'I will be carried along by belts I9 and will pass from the upper assembly into the space between the peripheries of the idlers on shaft I I and the belts driven from shaft I Il, but as the belts driven from shaft I0 travel slower than those driven from shaft Il,

the material of strip 21 will be compressed in the space between the points where the belts I9 are tangent to the idlers on the two shafts Il) and I I. If the gears I4 and I5 are interchanged, the material will be subjected toa stretching operation.

If a portion of the width of the strip only is to be stretched or compressed, some of the belts may be removed.

In the instant case, the strip 21 has a center gportion 28 of considerable thickness compared to the sides 29, and three belts are sufiicient as it is not necessary to alter the lengths of the sides 29, but where a strip of uniform thickness is treated, the number of belts depends on its width.

Although the machine illustrated is designed with `special reference for use with unvulcanized rubber composition, the principle involved can be employed for changing the length of other materials.

The compression or stretching is a continuous process and is uniform and fast.

In the drawing, the sheaves I6 have been shownof the same diameter and the shafts III and II operated at different speeds, but it is obvious that the same results can be obtained by rotating the shafts at the same speed and using sheaves of different diameters.

.Instead of the gears I4 and I5 shown, any suitable variable speed mechanism can be employed so as to permit the rate of speed to be readily altered to obtain the best results.

Instead of weights 24, springs or other equivalent means can be used to provide the necessaryv tension inthe belts.

- In the specification and on the drawing, the belts I9 have been so located that they lie in the plane of the idlers on the `other drive shaft, but this isf notan essential feature, but is desirable where-soft and pliable material is operated on.

In theV preferred form, which has been illustrated, the sheaves on the drive shafts and the corresponding sheaves on the idler shafts are so positioned that a tangent common to two cooperating sheaves will intersect the correspondidler on the other `drive shaft but the extent of this intersection can be varied until the chord reaches its minimum length and becomes a tangent and in some instances it may be pos- `,sible to obtain satisfactory results with thick "strips where the belts do not normally contact with the idlers.

Attention is called to the fact that the belts are substantially non-extensible and that there- -gfore each point along their lengths travel at the 5 same speed as distinguished from elastic belts that cooperate with spaced driving pulleys operating at different peripheral speeds. In this device, each set of belts are driven from a single drive shaft.

Having described the invention, what is claimed as new is:

l. A machine for changing the length of a strip of plastic material comprising, in combination, two parallel spaced drive shafts, means for interconnecting the shafts to obtain a constant speed ratio, a plurality of sheaves non-rotatably carried by each shaft, and spaced along the axis thereof, an idler located adjacent each sheave and mounted for free rotation relative thereto, the sheaves and the idlers on one shaft being in staggered relation relative to those on the other shaft, an idler-carrying shaft mounted in parallel relation with each drive shaft, idler sheaves mounted for rotation on the idler shafts, endless belts encircling the sheaves of each drive shaft and corresponding idler sheaves on the cooperating idler shaft, the sheaves being so located that a tangent common to a sheave on a drive shaft and a corresponding idler sheave will intersect the circumference of a corresponding idler on the other drive shaft, and means for driving the two sets of endless belts at different lineal speeds when the machine operates.

2, A machine for changing the lengthof a strip of plastic material comprising, in combination, two parallel spaced drive shafts, means for interconnecting the shafts to obtain a constant speed ratio, a plurality of sheaves non-rotatably carried by each shaft. and spaced along the axis thereof, an idler located adjacent each sheave and mounted for free rotation relative thereto, the sheaves and the idlers on one shaft being in staggered relation relative to those on the other` ingly maintaining a substantially constant tension'l in the two groups of belts.

3. A machine for changing the length of a strip of plastic material comprising, in combination, two parallel spaced drive shafts, means for interconnecting the shafts to obtain a constant speed ratio, a plurality of sheaves non-rotatably carried by each shaft and spaced along the axis thereof, an idler located adjacent each sheaveV and mounted for free rotation relative thereto, the sheaves and the idlers on one shaft being in staggered relation relative to those on the other shaft, an idler-carrying shaft mounted in parallel relation with each drive shaft, idler sheaves mounted for rotation on the idler shafts, endless belts encircling the sheaves of each drive shaft, and corresponding idler sheaves on the cooperating idler shaft, the sheaves being so located that a tangent common to a sheave on a drive shaft and a corresponding idler sheave will intersect the circumference of a corresponding idler on l the other drive shaft, means for driving the two sets of endless belts at different lineal speeds when the machine operates, the idler sheave shafts being mounted for movement towards and away from their cooperating drive shaft, and -yielding means for producing a force tending to move them away from their cooperating drive Shaft whereby the cooperating set of belts will be maintained under tension.

4. A machine for changing the length of a strip of plastic material comprising, in combination, two parallel spaced drive shafts, means for interconnecting the shafts to obtain a constant speed ratio, a plurality of sheaves non-rotatably carried by each shaft and spaced along the axis thereof, an idler located adjacent each sheave and mounted for free rotation relative thereto, the sheaves and the idlers on one shaft being in staggered relation relative to those on the other shaft, an idler-carrying shaft mounted in parallel relation with each drive shaft, idler sheaves mounted for rotation on the idler shafts, endless belts encircling the sheaves of each drive shaft, and corresponding idler sheaves on the cooperating idler shaft, the sheaves being so located that a tangent common to a sheave on a drive shaft and a corresponding idler sheave will inrsect the circumference of a corresponding idler on the other drive shaft, means for' driving the two sets of endless belts at different lineal speeds when the machine operates, the idler sheave shafts being mounted for movement toward and away from their cooperating drive shaft, and yielding gravity-responsive means for producing a force tending to move them away from their cooperating drive shaft whereby the cooperating set of belts will be maintained under tension.

5. A machine for changing the length of a strip of plastic material comprising in combination a supporting frame, two spaced parallel drive shafts rotatably carried by the frame, means for maintaining a fixed ratio of rotation between the shafts, a pair of levers pivotally connected to the frame adjacent each drive shaft, an idler-carrying shaft supported by each pair of levers, the idler shafts being so positioned relative to the drive shafts that a line joining an idler shaft and the drive shaft that cooperates with it will be intersected by a perpendicular from it to the other drive shaft, a plurality of sheaves non-rotatably secured to each drive shaft and spaced apart thereon, an idler mounted for free rotation adjacent each sheave, the idlers being of longer diameter than the sheaves, the idlers and sheaves on the two drive shafts being arranged in staggered relation, a plurality of idler sheaves on each idler shaft, endless belts encircling the sheaves on each drive shaft and corresponding idler sheaves, means for producing a yielding force on each pair of levers tending to turn them in a direction to tighten the belts, and means for imparting to the two sets of belts different lineal speeds.

6. A machine for changing the length of a strip of plastic material comprising, in combination, two parallel spa-ced drive shafts, means for interconnecting the shafts to obtain a desired speed ratio, a plurality of sheaves non-rotatably carried by each shaft, and spaced along the axis thereof, an idler located adjacent each sheave and mounted for free rotation relative thereto, an idler-carrying shaft mounted in parallel relation with each drive shaft, idler sheaves mounted for rotation on the idler shafts, endless belts encircling the sheaves of each drive shaft and corresponding idler sheaves on the cooperating idler shaft, the sheaves being so located that a tangent common to a sheave on a drive shaft and a corresponding `two parallel spaced drive shafts, means for interconnecting the shafts to obtain a desired speed ratio, a plurality of sheaves non-rotatably carried by each shaft, and spaced along the axis thereof,

an idler located adjacent each sheave and mounted for free rotation relative thereto, the sheaves and the idlers on one shaft being in staggered relation relative to those on the other shaft, an idlercarrying shaft mounted in parallel relation with each drive shaft, idler sheaves mounted for rotation on the idler shafts, endless belts encircling the sheaves of each drive shaft and corresponding idler sheaves on the cooperating idler shaft, and means for driving the two sets of endless belts at different lineal speeds when the machine operates.

8. A machine for changing the length of a strip of plastic material comprising, in combination, two parallel spaced drive shafts, means for interconnecting the shafts to obtain a desired speed ratio, a plurality of sheaves non-rotatably carried by each shaft, and spaced along the axis thereof, an idler located adjacent each sheave and mounted for free rotation relative thereto, an idler-carrying shaft mounted in parallel relation with each drive shaft, idler sheaves mounted for rotation on the idler shafts, endless belts encircling the sheaves of each drive shaft and corresponding idler sheaves on the cooperating idler shaft, and means for driving the two sets of endless belts at different lineal speeds when the machine operates.

9. A machine for changing the length of a tion, two parallel spaced drive shafts, means for interconnecting the shafts to obtain a desired speed ratio, a plurality of sheaves non-rotatably carried by each shaft and spaced along the axis thereof, an idler located adjacent each sheave and mounted for free rotation relative thereto, the sheaves and the idlers on one shaft being in staggered relation relative to those on the other shaft, an idler-carrying shaft mounted in parallel relation with each drive shaft, idler sheaves mounted for rotation on the idler shafts, endless belts encircling the sheaves of each drive shaft, and corresponding idler sheaves on the cooperating idler shaft, means for driving the two sets of endless belts at different lineal speeds when the machine operates, and means for yieldingly maintaining a substantially constant tension in the two groups of belts.

10. A machine for changing the length of a strip of plastic material comprising, in combination, two parallel spaced drive shafts, means for interconnecting the shafts to obtain a desired speed ratio, a plurality of sheaves non-rotatably carried by each shaft and spaced along the axis thereof, an idler located adjacent each sheave and mounted for free rotation relative thereto, an idler-carrying shaft mounted in parallel relation with each drive shaft, idler sheaves mounted for rotation on the idler shafts, endless belts encircling the sheaves of each drive shaft, and corresponding idler sheaves on the cooperating idler shaft, the sheaves being so located that a tangent common to a sheave on a drive shaft and a corresponding idler sheave will intersect the circum- .40 strip of plastic material comprising, in combina- CRS.

the moving belts. l 13. A machine for eifecting a uniform change ference of a corresponding idler on the other drive' shaft, means for driving the two sets of endless belts at different lineal speeds when the machine operates, and means for yieldingly ymaintaining a substantially constant tension in the two groups ofrbelts.

11. A machine for changing the length of a strip of plastic material comprising, in combination, two parallel spaced drive shafts, means for interconnecting the shafts to obtain a desired speed ratio, a plurality of sheaves non-rotatably carried by each shaft and spaced along the axis thereof, an idler located adjacent each sheave and mounted for free rotation relative thereto, an idler-carrying shaft mounted in parallel relation with each drive shaft, idler sheaves mounted for rotation on the idler shafts, endless belts encircling the sheaves of each drive shaft, and corresponding idler sheaves on the cooperating idler shaft, means for driving the two sets of endless belts at different lineal speeds when the machine operates, and means for yieldingly maintaining a substantially constant tension in the two groups of belts.

12. A machine for changing the length of a strip of plastic material comprising in combination, two strip propelling devices, operating to move the strip in the same direction, each Ydevice operating at a different speed, each device comprising a plurality of substantially non-extensible belts for engaging one side of the strip, land a means for holding the strip in contact with in vthe length of each unit length of a moving strip of plastic material, comprising two strip feeding devices, each of which has as one element thereof, a plurality of endless, substantially non-extensible belts for contacting one side of the strip, movable means for forcing the strip against the belts of each device, the belts of the two devices operating at different speeds, wiier'e-i by the strip, as it is transferred from one device to the other, is subjected to a change in length.

14. A machine for changing the length of a strip of plastic material, comprising two strip feeding devices, each of which has, Yas an element, a plurality of endless, substantially nonextensible belts, the belts on each device encircling pulleys on spaced parallel shafts, means associated with the belts of each device for urging the strip against the outside of the belts, and means for moving the belts in the same direction but at different speeds, whereby that portion of the strip lying between the two propelling devices will be changed in length.

15, A machine for changing the length of a strip of plastic material comprising in combination, two strip propelling devices, operating to move the strip in the same direction, each device operating at a different speed, each device comprising a substantially non-extensible belt for engaging a side of the strip, the belts each engaging a different side of the strip, and means positioned on opposite sidesV of the strip for forcing the other side thereof into contact with one of the belts.Y

16. A machine for changing the length of a strip of plastic material comprising in combination, two strip propelling devices formed from two assemblies, each of which comprises two spaced parallel shafts, one of which is a drive shaft, a drive pulley on the drive shaft, an idler pulley on the other shaft and a belt encircling the two pulleys, means for driving the belts at different lineal speeds, the shafts of one assembly being staggered with respect to those of the other assembly, but parallel therewith, and means on each assembly for urging longitudinally spaced parts of a plastic strip, positioned between the assemblies, against the belt of the other assembly.

, JOHN H. V. FINNEY. 

